Soap composition



SOAP CGIWPOSITIQN Victor C. Fusco, Baltimore, Md, and Richard C.Harshman, Kenmore, N. Y., assignors to Olin Matlneson ChemicalCorporation, a corporation of Virginia No Drawing. Application April 14,1955, Serial No. 501,436

6 Claims. (Cl. 260398.5)

This invention relates to improved compositions containing fatty acidradicals including fats, oils, soaps and soap products. Moreparticularly, it relates to soap compositions stabilized with respect tocolor and odor formation by the incorporation therein of azines.

' The tendency of soaps to discolor and become rancid in storage or useis well known. These effects have been attributed to a variety of causesincluding the manufacture of soaps from fats and oils which themselvestend to become rancid. It is also believed that minor metalliccontaminants, particularly iron and copper in minute amounts, acceleratethe formation of oxidation products resulting in undesirable odor ordiscoloration. These effects may appear in various forms of soapincluding bar soap, powdered soap, granulated soap and spray-dried soapsin the form of beads.

' The principal method of attack of this problem has been to add variousanti-oxidants or other stabilizers to soap compositions in an effort toovercome these undesirable effects. Many of the suggested stabilizersafford a partial solution, for example, in inhibiting odor formationwithout atfecting or even in deleteriously affecting color stability.

It has now been discovered that soap compositions can be stabilized bythe incorporation therein of minor amounts of azines. Effective amountsvary from about 0.05 percent to about one percent by weight of suchazines.

Suitable azines for use in the present invention can be obtained by thereaction of hydrazine with aldehydes or ketones in known ways. Thealdehydes and ketones can be aliphatic, aromatic, alicyclic orheterocyclic. The ketones can contain more than one of these types orgroups. Suitable aldazines include acetalazine, benzalazine,tetrahydrofurfuralazine, salicylalazine and cinnamalazine. Azines fromketones include dimethylketazine from acetone and methylbenzylketazinefrom methylbenzyl ketone. Mixtures of two or more azines can be used orthey may be used in conjunction with other known compatible stabilizers.

The stabilizers should not be added at a stage which will result indecomposition, leaching, or deterioration of the stabilizing agent. Theyare suitably incorporated in the soap compositions at any convenientstep after the saponification. For example, they can be added to theneat soap as made in the kettle in the manufacture of frame soap. In themanufacture of milled soap, it is ordinarily preferable to add thestabilizer to the mixer preceding the milling together with perfumematerials and coloring agents if desired. The stabilizer can also beincorporated during the crutching process. The stabilizers can be addedconveniently in the form of aqueous suspensions or they can beincorporated as dry solids, preferably finely divided. Mixing subsequentto the addition of the stabilizer is suflicient to render the soapcomposition homogeneous.

The soap product can subsequently be dried and formed into cakes,plates, beads or other forms as desired. In

2,813,112 Patented Nov. 12, 1957 the manufacture of liquid soapcompositions the stabilizers are suitably dissolved directly in the soapsolutions.

The stabilizers are effective in soaps of various types, includinglaundry soaps, facial soaps and in soaps subsequently incorporated incosmetic compositions including tooth paste, face creams and bodycreams.

The stabilizers of the present invention are also effective in delayingthe oxidative deterioration of fatty materials generally as well as thesoaps for which they are especially suited. Minor proportions of thesestabilizers are effective in fats, fatty oils and other esters ofunsaturated fatty acids as Well as inks, paints, varnishes, enamels andother materials containing them.

Example I A blend of dried pure soap stock (essentially the sodium soapof fatty acids derived from tallow) was prepared by thoroughly mixing0.5 parts by weight of benzalazine with 99.5 parts by weight of the soapat about room temperature. The mixture was pressed into 20 gram barsunder a pressure of 2000 p. s. i. g. Four test bars together with foursimilar bars prepared by the same procedure but omitting the benzalazinewas stored in an oven at 110 C. for seven days. At the end of thisperiod the light reflected from the surface of the blocks was measuredwith a Hunter reflectometer. Taking the reflectance of the soapimmediately after preparation as percent, the test bars without anyoxidant after the seven day heating period showed an average reflectanceof 56.0 percent while the bars containing 0.5 percent of benzalazineshowed an average light reflectance of 81.0 percent. These data showthat color development was very materially inhibited by thevincorporation of the benzalazine in the soap.

Example II A blend of benzalazine and soap (essentially the sodium soapof fatty acids derived from tallow) was prepared as described in ExampleI using only 0.05 weight percent of benzalazine based on the soap. Afterthe seven day heating at C., the average reflectance of four untreatedsoap bars was 30.5 percent of the soap bars before exposure. Four barscontaining 0.05 percent of benzalazine showed an average reflectance of52.3 percent.

Example III Three diiferent azines were blended with a purified anddried Bradford" white soap flakes (essentially the sodium soap of fattyacids derived from tallow) to form compositions containing 0.05 weightpercent of the azine. Each blend was pressed into four ZO-gram blocks at2000 p. s. i. g. The blocks were aged in an oven at 100-110 C. for sevendays. After the aging treatment the reflectance of light from thesurface of each block was measured with a Hunter refiectometer andcompared to an untreated soap block without an additive. The results,each an average of four tests, are shown in the following table:

Example IV Two 50 gram samples of freshly churned, unsalted butter, onecontaining 0.5 weight percent of benzalazine dissolved therein, wereplaced in 240 milliliter glass stoppered Erlenmeyer flasks. To eachflask was added a 7 centimeter circle of filter paper torn in smallpieces and wetted with one milliliter of water. The flasks werestoppered and placed in an oven at 80 C. for several days. A rancid odordeveloped in the, untreated sample after 3, days but the stabilizedsample was still sweet when the test was discontinued after 7 days.

Various modifications can be made in the procedures of the specificexamples to provide other improved soaps and soap-containingcompositions-falling within the scope of our invention. Our invention isgenerally applicable for the purpose of improving the properties ofsoaps and soap-containing compositions as .those terms are generallyunderstood in the art. In the specific examples, the soaps employed weresodium soaps of tallow fatty acids. Other soaps can be substituted forthose specifically used, and our invention comprehends the improvementof soaps and compositions containing them in which the cationic portionis, for example, ammonia, an amine, an alkali metal or an alkaline earthmetal, such as sodium, potassium, lithium, calcium, barium, and soforth, as well as magnesium, aluminum, zinc and cadmium. The anionicportion of the soap is generally derived from one or more aliphaticmonocarboxylic acids containing from 12 to 18 carbon atoms, such aslauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, andso forth. The soaps suitable for use in our invention can also bederived in known manner from a wide varietyof naturally-occurringmaterials or derivatives thereof, including tallow, palm oil,hydrogenated marine oils such as whale oil, coconut oil, palm kerneloil, rosin, tall oil, lard, olive oil, cottonseed oil, peanut oil, soyabean oil, linseed oil and so forth.

A wide variety of azinescan suitably be employed for the purpose ofpreparing our improved soap and soapcontaining products. Thus, theazines can be those derived, for example, from aliphatic aldehydes,including aldehydes of the type 'RCHO- wherein R is an alkyl radicalhaving from 2 to 12 carbon atoms, such as acetaldehyde, propionaldehyde,butyral'dehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde,caproaldehyde, enanthaldehyde, caprylaldehyde, pelargona-ldehyde,capraldehyde andlauraldehyde. As is apparent-from the specific examples,the azineswwhich can be used in preparing our improved soap andsoap-containing compositions can be derived from. aromatic aldehydes,among which are benzaldehyde, p-tolualdehyde, Y p-isopropylbenzaldehyde,ochlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde,p-nitrobenzaldehyde, salicylaldehyde, anisaldehyde, vanillin,veratraldehyde, piperonal, phenylacetah. dehyde and cinnamaldehyde.Azines derived from furfural and tetrahydrofurfural can also be suitablyemployed.

The azines which can be used in accordance with our invention can alsobe derived from a wide variety of aliphatic ketones, particularly.dialkyl ketones, including acetone, methyl ethyl ketone, methyl n-propylketone, methyl isopropyl ketone, diethyl ketone, methyl n-butyl ketone,.methyl isobutyl ketone, pinacolone, methyl namyl ketone, ethyl n-butylketone, di-n-propyl ketone, diisopropyl ketone, methyl n-hexyl ketone,6-methyl-2-heptanone, diisobutyl' ketone, methyl n-nonyl' ketone andstearone. The azines can also'be derived from alicyclic or aromaticketones, such as cyclopenta'none, cyclohexanone, acetophenone andbenzophenone.

Azines may also be incorporated in greases. These are commonlysoap-thickened petroleum oils containing lithium, sodium, calcium,aluminum or other metal soaps of various acids including those derivedfrom tall oil, tallow, castor oil or waste fat acids, for example.

We claim:

1. A soap composition containing a soap of an aliphatic monocarboxylicacid containing from 12 to 18' carbon atoms and containing as astabilizer an azine in amount from 0.05 to 1 percent by weight, baseduponthe weight of the soap.

2. A composition according to claim 1 in which the soap is a sodiumsoap. 7

. 3. A composition according to claim 1 in which the azine isbenzalazine.

4. A composition according to claim 1 in which the,

, azine is dimethylketazine.

5. A composition according to claim 1' in-which the azine issalicylalazine.

6. A composition according to claim 1 in which the azine iscinnamalazine.

1. A SOAP COMPOSITION CONTAINING A SOAP OF AN ALIPHATIC MONOCARBOXYLICACID CONTAINING FROM 12 TO 18 CARBON ATOMS AND CONTAINING AS ASTABILIZER AN AZINE IN AMOUNT FROM 0.05 TO 1 PERCENT BY WEIGHT, BASEDUPON THE WEIGHT OF THE SOAP.